crypto: talitos - prepare for adding ahash algorithms

No functional changes.
Use a union in talitos_alg_template for the crypto_alg
so that we can add a member later for ahash_alg.

Signed-off-by: Lee Nipper <lee.nipper@gmail.com>
Acked-By: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>